Mercury Rising - 1966 Cyclone

The Stellar Transformation of a 1966 Cyclone

Feature Article from Hemmings Muscle Machines

One of these days, somebody ought to get out the calligraphy quills and start inking the definitive codex of what making an American performance automobile is really all about. Aw, why wait? Let's do it here, together, just us.
Whaddaya really want with muscle? Go fast, look sharp, end the day with a few scoots in your jeans. As a blueprint on getting it done, you could do far worse than to follow the buildup of this 1966 Mercury Comet Cyclone, whose relatively simple visual effects and all-but-factory appearance don't even hint at the savvy thought that led to its creation.
At its purest, this is a tale of numbers: cost (manageable), displacement (booming), and elapsed times (in consistent descent). The transformation of this Comet into a nastily hooking-and-honking drag car--one that still happens to be a completely usable everyday streeter--is logical and organized, and quite smart.
In terms of nearly everything save for final engine assembly, it's the handiwork of Bob Dennison from Waltham, Massachusetts, who's disciplined about quantifying both expenditures and tick-tock results. What happened here, in simple terms, was that Bob executed the melding of a tossed-off, significantly enlarged Windsor block with icon of the Nineties, a Tremec five-speed, and stirred in some twist-restricting launch control. It's a straight-up skull-basher, probably 400hp at the clutch plate, with legit 11-second potential that's quite capable of walking along at the dinner hour along Route 128.
"Originally, I was going to go with a big-block in it, either the 390 or the 428 out of a passenger car," Bob explained. "When I got this car, it had the normal Ford 289 in it, with cast-iron block and heads. Price-wise, the FE engines will end up costing you twice as much to do by the time you're done with them. You have companies like Eagle and SCAT that have been coming out with FE stroker kits, but they're expensive. Plus, a lot of those FE blocks ended up being tossed in the trash. It's hard to find a usable block that hasn't been so scored that it can be rebuilt."
While deliberating, Bob had a 351 Windsor block lying on his shop floor that was discarded (if you're going to judge it strictly), but in worlds better condition than any Dumpster find. A friend had pulled it out of his 1994 Ford F-350 pickup, planning a rebuild, but gave it to Bob instead.
What a gift: "The later-model W-blocks have deeper lifter bores, which make it a lot easier to use a roller cam, plus they're a lot cheaper, even when they're not completely free. Not only that, you can use the same roller lifters that Ford makes for a 302 Mustang. The availability of parts now for them is outrageous. Twenty-five years ago, I was building a Cougar with a 351 and you couldn't find anything. You couldn't even find a decent head for a small-block Ford. Today, there's probably 20 of them, easy."
One thing Bob will tell you, for emphasis, is that throughout the Cyclone whirl-up, he did his homework. A sizable part of that is having identifiable, achievable goals--in his case, the 11s with an easily attainable 400hp at the flywheel. That dictated the perfectly cornered peg of current pushrod performance theory, a small-block measuring around 400 cubic inches and nearly square bore and stroke measurements.
As produced by Ford, the latter-day truck Windsor, used through 1997, utilized a 4.00-inch bore with a 3.50-inch stroke. Bob wanted those numbers to match, with the factored-in consideration of also hitting a compression-ratio bull's-eye of 10.6 or 10.7:1, so the engine could be workable on the street while drinking premium unleaded.
His aftermarket search led him to a rotating-assembly kit by Eagle Performance Products, designed to displace 408 cubic inches; the setup was intended to be balanced externally by the engine builder. Its forged-steel 4340 crankshaft has offset throws for the needed stroke clearance, with a center counterweight. That kit includes Eagle SIR 5140 H-beam forged-steel connecting rods, which are "Sunnen-sized," with ARP fasteners throughout.
Using his domino-theory reasoning, Bob chose the kit as furnished with SRP forged-aluminum domed pistons, the choice called in part by the tech advisor to max out the punch from the Edelbrock Performer RPM heads' 58cc combustion chambers--most stock FE heads measure 60 to 62cc, with a little less robust squeeze--again with an eye on the compression target. For the same reason, the pistons got Speed Pro plasma moly rings. Century Automotive Machine in Waltham, which did the assembly work, mildly polished up the out-of-carton ports.
Startling time slips not withstanding, this Comet is a street car at its core. Factoring into Bob's calculations and goals was the parameter of achieving peak power and torque downstream from 6,000 RPM. With that in mind, he jumped on the phone to Memphis, Tennessee, and the helpful techies at Comp Cams.
At the outset, he was mulling lift numbers in the .600- to .610-inch range, but agreed that sort of refrigerator-heaving was a plea for breakage boo-hoos. Comp Cams cooked him some numbers on a custom roller grind--for about $350, we should note--with .580 lift on both the intake and exhaust sides and corresponding duration degrees of 236 and 248, set up with 112 degrees of lobe separation. Comp Cams also provided the aluminum roller rockers (1.6:1 ratio) and 120-pound valve springs. According to Bob's calculations, peak power's now available at 5,980 RPM with 4 degrees of advance.
There's little in this Comet that isn't either economical, or whose worth has stood Bob's continuously empirical cataloging of time slips. He went with a single-plane Edelbrock Victor Jr. aluminum intake manifold. How come? Because he cut a good deal for it at the swap meet. The cam tech recommended a single-plane flow rate that led Bob to select a Holley 830 CFM double-pumper, with the choke tower removed and Proform float bowls with visual adjustment. For a disciplined, accurate burn, he selected MSD ignition with a billet distributor.
Any 1966 Comet hardtop is an unexpected sight today. Lincoln-Mercury built 6,889 Comet Cyclone two-doors in 1966; the quantity of au naturel four-speed examples, including this one, is an even less visible number. More than 70 percent of all midsize 1966 Mercurys had automatics, so we're hardly talking 1970 Chevelle SS quantities here. It was complete when Bob bought it in 2002, with the major body updates since then limited to a few repaintings--the final color is still up in the air--and fresh chrome on the rear bumper.
Going to a five-speed, however, was a prime original objective. He took $1,320 to Forte's Parts Connection, an established supplier of hardcore performance driveline pieces in Framingham, Massachusetts, and went home with a new 2002 Tremec TKO-500 five-speed with an 11.5-inch Weber diaphragm clutch. The gearbox is specifically built for aftermarket Ford use, the number declaring its torque-poundage capability. As delivered, it's 31.24 inches long; Forte's whittled down the input shaft a tad for tighter installation fit.
The inseparable triumvirate of factors in modern drag-strip performance are reaction, hook and consistency. For an almost totally stock-appearing and realistically used car, the Comet has measurable chassis upgrades. The most basic were welded-in subframe connectors and a driveshaft loop. To aid weight transfer, Bob installed Moog front coils originally intended for big-block Ford noses, and added a fifth leaf to the rear eye-mounted semi-elliptics, an orthodox enough stiffening method.
Most people in deep straight-line thought realize that consistency is the offspring of both rigidity and adjustability. Bob started out with commonplace rear under-riders--glorified slapper bars with little in the way of tuning capability. Dampening the stock 3.89:1 Detroit Locker axle was vital, so Bob upgraded to CalTracs 6300 traction bars, produced by Calvert Racing. They're expressly designed for use with street or bracket-type cars running with multi-leaf rear springs.
Aside from having extreme bolt-on simplicity, they're highly tunable. The forward pivot's bolting positions relocate the car's instant center, while the threaded center transfer link can be tweaked with a wrench.
"There's probably 10 to 15 turns of adjustability in the lower link. The harder you crank it down, in maybe half-turn increments, the harder it launches," Bob assessed. "Most of your adjustment at the race track is done by lengthening the bottom bar. Since I've started working with the CalTracs, I've probably picked up a half second and maybe 3 MPH."
The Comet's rake is essentially stock with none of the typical "Shelby drop" in evidence. Bob fitted Competition Engineering adjustable drag shocks, set to 60/40 up front and 40/60 at the rear. The Ford manual steering, however, is stock, along with the half-inch solid front anti-roll bar.
With the 289, Bob's best shot in the Comet had been about a 13.70. The engine transplant, and subsequent chassis experimentation, has dropped his times to strongly consistent 11.90s, most of them clocked at New England Dragway in Epping, New Hampshire, near the coast and about 90 feet above sea level. The Comet checks in at 3,480 pounds with fluids and driver.
"There should be some 11.50s in it, if I'm lucky," he forecast. "I'm still in the process of figuring out how to get it dialed in with tire pressures and the CalTracs, which have made the biggest difference of everything I've done. Remember, this is still a street car, running on 94-octane unleaded, and I like driving it. I'll take it 300 miles round-trip to Lebanon Valley Dragway in New York, or 1,000 miles round-trip to the Ford show at Carlisle. No problems, and I'm still getting about 19 MPG."
OWNER'S VIEW
I like different things. I love the old Mercury Cougars, and I used to own a bunch of them. I love the 1967 Camaro, too. My favorite car of all time, I'd have to say, is the 1969 Dodge Super Bee with the 440 Six Pack.
But I love Fords, all kinds of Fords, because I grew up with them. You don't see many two-door Mercurys from the 1960s anymore, either Comets or Cyclones, so when this one became available in New Hampshire, I bought it.
The neatest thing about the Comet, practically, is when you park it. I can leave it anywhere, walk away from it, turn around and almost immediately, spot people walking up to it to check it out. With the Torq-Thrust wheels and the fact that it's a 1960s Ford product, a lot of people think it's some kind of A/FX or Super Stock car.--Bob Dennison
PROS & CONSPROS
+ Delightfully unusual styling
+ Hooks hard on demand
+ Peak power sans breakage
CONS
- Finding a complete car is vital
- Lethargic manual steering
- Trim parts can be scarce
SpecificationsEngine
Block type: Ford 351 Windsor 90-degree cast-iron V-8
Cylinder heads: Edelbrock Performer RPM cast aluminum
Displacement: 408 cubic inches
Bore x Stroke: 4.030 x 4.000 inches
Compression ratio: 10.7:1
Pistons: Eagle Products SRP cast aluminum
Connecting rods: Eagle SIR 5140 forged steel H-beam
Horsepower @ RPM: 411.25 @ 6,000
Torque @ RPM: 433.85-lbs.ft. @ 4,100
Camshaft type: Comp Cams hydraulic roller, custom grind
Duration: 236 degrees intake, 248 exhaust
Lift: 0.580-inch intake and exhaust
Valvetrain: Edelbrock steel 2.02/1.60-inch valves, Comp Cams 1.6:1 ratio aluminum rocker arms, Comp Cams beehive-type valve springs, Ford Racing hydraulic roller lifters
Fuel system: Holley 830-CFM four-barrel carburetor w/dual accelerator pumps (double-pumper), Proform float bowls, Carter mechanical 120-GPH fuel pump, Edelbrock Victor Jr. single-plane aluminum intake manifold
Ignition system: 12-volt, MSD billet aluminum distributor
Exhaust system: Hooker Super Comp tubular steel headers, Flowmaster mufflers, 3-inch dual pipes
Original engine: Ford 289-cu.in. small-block V-8
Transmission
Type: Tremec TKO-500 five-speed manual, all synchro, 11.5-inch Weber diaphragm clutch
Ratios 1st: 3.27:1
2nd: 1.98:1
3rd: 1.34:1
4th: 1.00:1
5th: 0.68:1
Reverse: 2.95:1
Differential
Type: 1966 Ford 9-inch housing with Detroit Locker differential
Ratio: 3.89:1
Steering
Type: Ford recirculating ball, manual
Ratio: 16.0:1
Brakes
Front: Kelsey-Hayes 11.5-inch ventilated discs, four-piston calipers
Rear: Ford 9.0-inch expanding drums
Suspension
Front: Ford control arms with 1/2-inch solid anti-roll bar, Moog coil springs, Competition Engineering adjustable shock absorbers, welded Crites subframe connectors
Rear: Semi-elliptic springs w/five leaves, CalTracs adjustable traction arms, Competition Engineering adjustable shock absorbers, welded Crites subframe connectors
Wheels & Tires
Wheels: American Racing Torq-Thrust D cast alloy
Front: 15 x 6 inches
Rear: 15 x 8 inches
Tires: BFGoodrich radials
Front: 215/65R15
Rear: 275/60R15
Performance
Acceleration
1/4-mile ET: 11.98 @ 116.65 MPH (New England Dragway, elevation 90 feet)

This article originally appeared in the April, 2009 issue of Hemmings Muscle Machines.